Updated phone conversation systems

We have continued working on this project in our spare time after the GMTK game jam, and this is our first updated build since then. We've mostly been improving content generation tools and underlying systems, as well as producing more environmental art. We'll be turning this into an actual game soon, but for now the main improvement is in the mobile phone branching conversation system. It's been updated to have an interface more representative of what phone messaging should look like, as well as support for emojis.